[sdiy] OTA to voltage-control resonance?

[Aaron Lanterman]

On Aug 30, 2009, at 7:52 PM, Jerry Gray-Eskue wrote:

> If you put it in the feed back loop I believe you will need the  
> "Floating
> Voltage Controlled Resistor" shown in figure 10 of the National  
> LM13700 data
> sheet.

Some of my students tried that - if I recall correctly it acted kinda  
iffy.

> I think the main reason the circuit is not widely used is that the  
> more
> common voltage control techniques work as well or better and require  
> less
> complexity.

Yes - you can figure out what your feedback is feeding into and design  
some appropriate variable gain element that's simpler.

- Aaron